PTH-related peptide-like immunoreactivity in the median emminence, paraventricular and supraoptic nuclei in colchicine-treated rats.
The existence of PTH-related peptide (PTHrP) in the hypothalamus was examined by immunohistochemistry in colchicine-treated rats. Two days after intracerebroventricular administration of colchicine dense PTHrP-like immunoreactivity (LI) was observed in the external zone of the median emminence (ME). PTHrP-LI cells were found in the paraventricular nucleus, the supraoptic nucleus and the periventricular region of the third ventricule. The effects of PTHrP on intracellular Ca2+ concentrations ([Ca2+]i) were examined by a Ca2+ imaging method using fura-2 in perifused preparations of isolated rat anterior pituitary cells. The rise in [Ca2+]i induced by PTHrP was found in approximately 17% of the cells examined. These results suggest that PTHrP-LI cells in the hypothalamus may project to the ME and contribute to the anterior pituitary function.
Tokunaga
M
M
Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
Ueta
Y
Y
Isse
T
T
Hara
Y
Y
Tanaka
K
K
Yamamoto
S
S
Kabashima
N
N
Shibuya
I
I
Hattori
Y
Y
Yamashita
H
H
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002552:Cerebral Ventricles / Q000378:metabolism; D003078:Colchicine / Q000494:pharmacology*; D007150:Immunohistochemistry; D007425:Intracellular Membranes / Q000378:metabolism; D008297:Male; D008473:Median Eminence / Q000187:drug effects / Q000378:metabolism*; D009994:Osmolar Concentration; D044162:Parathyroid Hormone-Related Protein; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000378:metabolism*; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013495:Supraoptic Nucleus / Q000187:drug effects / Q000378:metabolism*
D044162:Parathyroid Hormone-Related Protein; D011506:Proteins; D003078:Colchicine; D002118:Calcium